The present invention relates to a resin-encapsulated semiconductor device, and more particularly to techniques which are effective when applied to technology for packaging a large-sized semiconductor chip.
In a resin-encapsulated semiconductor device, as the size of a semiconductor chip becomes larger, the spacing between the side of a package and the tab thereof being a portion for mounting the semiconductor chip tends to narrow more. This is ascribable to the fact that, in spite of the enlargement of the size of the semiconductor chip (pellet), the size of the package for receiving the semiconductor chip is standardized and cannot be enlarged.
Especially in a conventional semiconductor integrated circuit device of the memory type, a dual in-line type resin-sealing package having a bent width of 300 mils (7.62 mm) is used.
With rise in the density of integration, the memory type semiconductor integrated circuit device has had its semiconductor chip enlarged in the lengthwise direction thereof. In addition, the memory type semiconductor integrated circuit device has the feature that bonding pads in the semiconductor chip are chiefly arranged along both of the shorter sides of the semiconductor chip which is formed in an elongated or rectangular shape.
Accordingly, there is the problem that, when the density of integration in the memory type semiconductor integrated circuit device is increased, it becomes very difficult to maintained a bent width of 300 mils in the dual in-line type resin-sealing package. The reason is that, when the semiconductor chip which is enlarged and elongated and in which the bonding pads thereof are chiefly arranged along the shorter sides is to be placed in the dual in-line type resin-sealing package whose lateral width (i.e. shorter sides) is limited, a the wiring space available for inner leads in the package becomes insufficient.
It is therefore desired to provide a semiconductor device comprising a resin-sealing package which can hold the wiring space required of inner leads adequately even in the case of encapsulating the enlarged and elongated rectangular shaped semiconductor chip that has the bonding pads arranged chiefly along the laterally shorter sides thereof.
In order to comply with such a desire, a semiconductor device stated below has been proposed:
The semiconductor device comprises a semiconductor chip, a plurality of leads which construct external terminals in a manner to be electrically independent of one another, pieces of bonding wire which bridge the respective leads and said semiconductor chip, and a package which seals said semiconductor chip, said leads and the bonding wire pieces with a resin; wherein inner portions (hereinbelow, also termed "inner leads") of, at least, some of said leads are laid under said semiconductor chip within said package, and an insulator layer is interposed between said inner leads and said semiconductor chip.
According to this semiconductor device, the inner leads of, at least, some of the leads are partly laid under the semiconductor chip within the resin-sealing package, so that a wiring space which is made available, for the inner leads can be sufficient. Accordingly, the inner leads can be satisfactorily wired in the package even in the case where, by way of example, an enlarged and elongated semiconductor chip which has its bonding pads arranged chiefly along the shorter lateral sides thereof is to be placed in the dual in-line type resin-sealing package whose lateral width is limited.
Moreover, since the insulator layer is interposed between the semiconductor chip and the inner leads laid thereunder, the insulation between the semiconductor chip and the leads is adequately maintained, and the semiconductor chip can be firmly fixed within the resin-sealing package.
Incidentally, such semiconductor devices are explained in, for example, the official gazettes of Japanese Patent Applications Laid-open No. 114261/1982, No. 218139/1986 and No. 258458/1986.